1. Field of the Invention
The present invention relates to an apparatus and a method for controlling the height of a stack of sheets in sheet feeders for sheet processing machines.
2. Brief Description of the Background of the Invention Including Prior Art
Apparatus for control of stack heights are known (see for example German Democratic Republic Patent DD 124786) where the condition for exact control of the stack motion is achieved by an automatic adjustment to the printing speed in several speed steps and by a manual adjustment to the thickness of the sheets to be processed.
It is a disadvantage of the above process that the adjustment of the apparatus regarding the thickness of the sheets processed is not automatic. This results in either the hourly switch-on times of the devices getting excessively high or that the deviations of the stack sizes become so large as to result in disturbances in the processing steps.